Field of Invention
The present invention relates to a semiconductor memory device. More specifically, the present invention relates to a three-dimensional semiconductor memory device.
Description of Related Art
Semiconductor memory devices are being developed in various structures that are capable of increasing integration degree. One example of this is three-dimensional semiconductor memory devices.
Three-dimensional memory devices include memory cells which are stacked on a substrate along a channel film. Integration of a three-dimensional memory device is improved as the stacking of the three-dimensional memory cells increases. A three-dimensional memory device includes a memory block having a structure that is different from that of a two-dimensional memory device. Accordingly, in order to secure operational reliability, various technology developments suitable for the structures of the three-dimensional memory device are required.